A conventional grille shutter control device is disclosed in, for example, Patent Document 1. Basically, when the coolant temperature detected by a coolant temperature sensor is less than or equal to a predetermined temperature (for example, 80° C.), the device closes the shutter to prevent air from being introduced into the engine compartment, and improves warm-up performance of the engine. Also, when the coolant temperature detected by the coolant temperature sensor is greater than or equal to a predetermined temperature (for example, 90° C.), the device opens the shutter to introduce a large amount of air into the engine compartment, and cools the coolant circulating in a radiator.